This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. To identify plant cell wall factors limiting digestibility and forage utilization in sustainable dairy farming, we will 1. Characterize plants with genetically modified lignin-pathways in order to develop novel approaches for improving forage utilization and provide insight into the effects of lignin composition on cell wall digestability and formation of indigestible residues. 2. Determine the intrinsic chemical characteristics of indigestible residues in order to elucidate mechanisms that limit their digestion by dairy cows and reduce their negative impact.